SmallBasic Turtle Logo Source Code 3

This is my polished version of Logo Turtle example code implementation in Small Basic. I hope you can easily understand the code. The code is optimized for simplicity, not execution speed. I will be bringing you more examples as time goes by. I don't really teach, but hopefully, by showing you the source codes, this can be a self-guided tutorial for you.

'Turtle Logo in Small Basic - NMC672

'by Harry Hardjono

'Turtle angle speed x1 y1 x0 y0

'Turtle move moveto penup pendown

'Turtle turn turnleft turnright

'Turtle show hide

'

' I hope this program is a good tutorial on how you can do your own programs!

GraphicsWindow.Show()

GraphicsWindow.Clear()

'----------------------------------------------

' Example Turtle Operation Code

'----------------------------------------------

cmd1="init"

Toitle()

cmd1="size"

cmd2=10

Toitle()

Program.Delay(1000)

cmd1="color"

cmd2="green"

Toitle()

Program.Delay(1000)

cmd1="color"

cmd2="red"

Toitle()

Program.Delay(1000)

cmd1="size"

cmd2=4

Toitle()

Program.Delay(1000)

cmd1="size"

cmd2=8

Toitle()

For loop=0 to 360 Step 20

cmd1="moveto"

cmd2=sx/2

cmd3=sy/2

Toitle()

cmd1="turn"

cmd2=loop

Toitle()

cmd1="move"

cmd2=200

Toitle()

Program.Delay(1000)

endfor

beginloop:

GraphicsWindow.Clear()

cmd1="init"

Toitle()

Program.Delay(2000)

cmd1="show"

Toitle()

For loop=1 to 50

cmd1="penup"

Toitle()

cmd1="moveto"

cmd2=Math.GetRandomNumber(sx)

cmd3=Math.GetRandomNumber(sy)

Toitle()

cmd1="pendown"

Toitle()

cmd1="color"

cmd2=GraphicsWindow.GetRandomColor()

Toitle()

cmd1="size"

cmd2=Math.GetRandomNumber(10)

Toitle()

For loop2=1 to Math.GetRandomNumber(6)

cmd1="turn"

cmd2=Math.GetRandomNumber(360)

Toitle()

cmd1="move"

cmd2=Math.GetRandomNumber(1000)

Toitle()

endfor

endfor

Program.Delay(15000)

Goto beginloop

'----------------------------------------------

' Main Turtle function.

'----------------------------------------------

Sub Toitle

'cmd1=command (input)

'cmd2=param1 (input)

'cmd3=param2 (input)

If (cmd1="init") then

sy=GraphicsWindow.Height

sx=GraphicsWindow.Width

x0=0

y0=0

x1=sx/2

y1=sy/2

px=x1

py=y1

p=1

angle=180

col="blue"

speed=100

siz=1

ts=1

DrawTurtle()

elseif (cmd1="penup") then

p=0

elseif (cmd1="pendown") then

p=1

elseif (cmd1="move") then

'forward

x0=x1

y0=y1

x1=x0+cmd2*Math.Sin(Math.GetRadians(angle))

y1=y0+cmd2*Math.Cos(Math.GetRadians(angle))

draw()

elseif (cmd1="moveto") then

x0=x1

y0=y1

x1=cmd2

y1=cmd3

draw()

elseif (cmd1="turn") then

angle=cmd2

DrawTurtle()

elseif (cmd1="turnleft") then

angle=angle+cmd2

DrawTurtle()

elseif (cmd1="turnright") then

angle=angle-cmd2

DrawTurtle()

elseif (cmd1="color") then

col=cmd2

DrawTurtle()

elseif (cmd1="size") then

siz=math.Max(1,cmd2)

siz=math.Min(10,siz)

DrawTurtle()

elseif (cmd1="speed") then

speed=cmd2

speed=Math.Max(0,speed)

speed=Math.Min(100,speed)

elseif (cmd1="show") then

ts=1

elseif (cmd1="hide") then

ts=0

endif

If (ts=1) then

MoveTurtle()

ShowTurtle()

Else

HideTurtle()

endif

endsub

'Draw

Sub Draw

If (p>0) then

If (x0<>x1 or y0<>y1) then

m=math.Max(math.Abs(x1-x0),math.Abs(y1-y0))

map_var["mx1"]=0

map_var["mx3"]=m

For i=0 To m

map_var["my1"]=x0

map_var["my3"]=x1

map_var["mx2"]=i

map()

px=map_var["my2"]

map_var["my1"]=y0

map_var["my3"]=y1

map_var["mx2"]=i

map()

py=map_var["my2"]

RemBugFix()

px=Math.Remainder(px,sx)

py=Math.Remainder(py,sy)

GraphicsWindow.BrushColor=col

GraphicsWindow.FillEllipse(px,py,siz,siz)

MoveTurtle()

If (speed<100) then

Program.Delay(100-speed)

endif

EndFor

endif

endif

'These really need to be Mod

'Seems buggy - doesn't work with negative number?

RemBugFix2()

x1=Math.Remainder(x1,sx)

y1=Math.Remainder(y1,sy)

angle=Math.Remainder(angle,360)

endsub

'----------------------------------------------

'map function

'----------------------------------------------

Sub map

'x1-x2-x3 y1-y2-y3

'(x2-x1)/(x3-x1)=(y2-y1)/(y3-y1)

'y1+(y3-y1)*(x2-x1)/(x3-x1)=y2

map_var["my2"]=((map_var["my3"]-map_var["my1"])*(map_var["mx2"]-map_var["mx1"])/(map_var["mx3"]-map_var["mx1"]))+map_var["my1"]

EndSub

'----------------------------------------------

'Turtle Operations - Could've been Shape Operation had Rotate Triangle not buggy

'----------------------------------------------

Sub DrawTurtle

'Sets size, color, and rotation of Turtle

Shapes.Remove(TT) 'Nothing happens if you remove empty shape. Good!

DrawTurtle_local["tx1"]=(10+siz)*Math.Sin(Math.GetRadians(angle))

DrawTurtle_local["ty1"]=(10+siz)*Math.Cos(Math.GetRadians(angle))

DrawTurtle_local["tx2"]=(10+siz)*Math.Sin(Math.GetRadians(angle+140))

DrawTurtle_local["ty2"]=(10+siz)*Math.Cos(Math.GetRadians(angle+140))

DrawTurtle_local["tx3"]=(10+siz)*Math.Sin(Math.GetRadians(angle+220))

DrawTurtle_local["ty3"]=(10+siz)*Math.Cos(Math.GetRadians(angle+220))

GraphicsWindow.BrushColor=col

TT=Shapes.AddTriangle(DrawTurtle_local["tx1"],DrawTurtle_local["ty1"],DrawTurtle_local["tx2"],DrawTurtle_local["ty2"],DrawTurtle_local["tx3"],DrawTurtle_local["ty3"])

endsub

Sub MoveTurtle

'Move the turtle

Shapes.Move(TT,px+(siz/2),py+(siz/2))

endsub

Sub ShowTurtle

Shapes.ShowShape(TT)

endsub

Sub HideTurtle

Shapes.HideShape(TT)

endsub

'----------------------------------------------

' Various bug fix

'----------------------------------------------

Sub RemBugFix

While (px<0)

px=px+sx

EndWhile

While (py<0)

py=py+sy

EndWhile

endsub

Sub RemBugFix2

While (x1<0)

x1=x1+sx

EndWhile

While (y1<0)

y1=y1+sy

EndWhile

While (angle<0)

angle=angle+360

EndWhile

endsub

SmallBasic Turtle Logo Source Code 2

'Turtle Logo in Small Basic
'by Harry Hardjono
'Turtle angle speed x1 y1 x0 y0
'Turtle move moveto penup pendown
'Turtle turn turnleft turnright
'Turtle show hide
'
' I did this in one afternoon. Could've been faster if I ignore Show/Hide Turtle
' Updated with Shapes. Sure is a lot faster had I known this earlier!

GraphicsWindow.Show()
GraphicsWindow.Clear()

cmd1="init"
Toitle()
cmd1="size"
cmd2=8
Toitle()



For loop=1 to 360 Step 20
cmd1="moveto"
cmd2=sx/2
cmd3=sy/2
Toitle()
cmd1="turn"
cmd2=loop
Toitle()
cmd1="move"
cmd2=200
Toitle()
Program.Delay(1000)
endfor



beginloop:
GraphicsWindow.Clear()
cmd1="init"
Toitle()
Program.Delay(2000)
cmd1="show"
Toitle()

For loop=1 to 50
cmd1="penup"
Toitle()
cmd1="moveto"
cmd2=Math.GetRandomNumber(sx)
cmd3=Math.GetRandomNumber(sy)
Toitle()
cmd1="pendown"
Toitle()
cmd1="color"
cmd2=GraphicsWindow.GetRandomColor()
Toitle()
cmd1="size"
cmd2=Math.GetRandomNumber(10)
Toitle()
' Show Turtle is very slow!
' If (loop=10) Then
' cmd1="show"
' Toitle()
' ElseIf (loop=30) then
' cmd1="hide"
' Toitle()
' EndIf
For loop2=1 to Math.GetRandomNumber(6)
cmd1="turn"
cmd2=Math.GetRandomNumber(360)
Toitle()
cmd1="move"
cmd2=Math.GetRandomNumber(1000)
Toitle()
endfor
endfor
Program.Delay(15000)
Goto beginloop



Sub Toitle
'cmd1=command (input)
'cmd2=param1 (input)
'cmd3=param2 (input)
If (cmd1="init") then
sy=GraphicsWindow.Height
sx=GraphicsWindow.Width
'Bug: GetPixel does not take Background color
GraphicsWindow.BrushColor="white"
GraphicsWindow.FillRectangle(0,0,sx,sy)
x1=sx/2
y1=sy/2
x0=x1
y0=y1
p=1
angle=180
col="blue"
GraphicsWindow.BrushColor=col
siz=1
ts=1
SaveBG()
elseif (cmd1="penup") then
p=0
elseif (cmd1="pendown") then
p=1
elseif (cmd1="move") then
'forward
' LoadBG()
x0=x1
y0=y1
x1=x0+cmd2*Math.Sin(Math.GetRadians(angle))
y1=y0+cmd2*Math.Cos(Math.GetRadians(angle))
draw()
' SaveBG()
elseif (cmd1="moveto") then
' LoadBG()
x0=x1
y0=y1
x1=cmd2
y1=cmd3
draw()
' SaveBG()
elseif (cmd1="turn") then
LoadBG()
angle=cmd2
SaveBG()
elseif (cmd1="turnleft") then
LoadBG()
angle=angle+cmd2
SaveBG()
elseif (cmd1="turnright") then
LoadBG()
angle=angle-cmd2
SaveBG()
elseif (cmd1="color") then
col=cmd2
elseif (cmd1="size") then
siz=math.Max(1,cmd2)
siz=math.Min(10,siz)
elseif (cmd1="show") then
if (ts<>1) then
ts=1
SaveBG()
endif
elseif (cmd1="hide") then
LoadBG()
ts=0
endif

'These really need to be Mod
'Seems buggy - doesn't work with negative number?
' RemBugFix2()
'x1=Math.Remainder(x1,sx)
'y1=Math.Remainder(y1,sy)
'angle=Math.Remainder(angle,360)

If (ts=1) then
' DrawTurtle()
' Shapes.Move(TT,x1,y1)
Shapes.Move(TT,px+(siz/2),py+(siz/2))
endif

endsub

Sub DrawTurtle
tx1=10*Math.Sin(Math.GetRadians(angle))
ty1=10*Math.Cos(Math.GetRadians(angle))
tx2=10*Math.Sin(Math.GetRadians(angle+140))
ty2=10*Math.Cos(Math.GetRadians(angle+140))
tx3=10*Math.Sin(Math.GetRadians(angle+220))
ty3=10*Math.Cos(Math.GetRadians(angle+220))
TT=Shapes.AddTriangle(tx1,ty1,tx2,ty2,tx3,ty3)
endsub


Sub RemBugFix
While (px<0) px=px+sx EndWhile While (py<0) py=py+sy EndWhile endsub Sub RemBugFix2 While (x1<0) x1=x1+sx EndWhile While (y1<0) y1=y1+sy EndWhile While (angle<0) angle=angle+360 EndWhile endsub 'Draw Sub Draw If (p>0) then
If (x0<>x1 or y0<>y1) then
m=math.Max(math.Abs(x1-x0),math.Abs(y1-y0))
mx1=0
mx3=m
For i=0 To m
my1=x0
my3=x1
mx2=i
map()
px=my2
my1=y0
my3=y1
mx2=i
map()
py=my2
RemBugFix()
px=Math.Remainder(px,sx)
py=Math.Remainder(py,sy)
If (siz>1) then
GraphicsWindow.BrushColor=col
GraphicsWindow.FillEllipse(px,py,siz,siz)
else
GraphicsWindow.SetPixel(px,py,col)
endif
Shapes.Move(TT,px+(siz/2),py+(siz/2))
EndFor
endif
endif

'These really need to be Mod
'Seems buggy - doesn't work with negative number?
RemBugFix2()
x1=Math.Remainder(x1,sx)
y1=Math.Remainder(y1,sy)
angle=Math.Remainder(angle,360)

endsub

'map function
Sub map
'x1-x2-x3 y1-y2-y3
'(x2-x1)/(x3-x1)=(y2-y1)/(y3-y1)
'(y3-y1)*(x2-x1)/(x3-x1)=(y2-y1)
'y1+(y3-y1)*(x2-x1)/(x3-x1)=y2
my2=((my3-my1)*(mx2-mx1)/(mx3-mx1))+my1
EndSub


sub SaveBG
If (ts=1) then
DrawTurtle()



' BGc=0
' BGx1=Math.Floor(Math.Max(0,x1-10))
' BGx1=Math.Floor(Math.Min(sx,BGx1))
' BGy1=Math.Floor(Math.Max(0,y1-10))
' BGy1=Math.Floor(Math.Min(sy,BGy1))
' BGx2=Math.Floor(Math.Max(0,x1+10))
' BGx2=Math.Floor(Math.Min(sx,BGx2))
' BGy2=Math.Floor(Math.Max(0,y1+10))
' BGy2=Math.Floor(Math.Min(sy,BGy2))
' For BGy=BGy1 To BGy2
' For BGx=BGx1 To BGx2
' BGc=BGc+1
' BG_Array[BGc]=GraphicsWindow.GetPixel(BGx,BGy)
' EndFor
' endfor
' TextWindow.Write("SaveBG ")
' TextWindow.Write(BGx1)
' TextWindow.Write(" ")
' TextWindow.Write(BGy1)
' TextWindow.Write(" ")
' TextWindow.Write(BGx2)
' TextWindow.Write(" ")
' TextWindow.Write(BGy2)
' TextWindow.WriteLine(" ")
endif
endsub

Sub LoadBG
If (ts=1) then
Shapes.Remove(TT)

' BGc=0
' For BGy=BGy1 To BGy2
' For BGx=BGx1 To BGx2
' BGc=BGc+1
' GraphicsWindow.SetPixel(BGx,BGy,BG_Array[BGc])
' EndFor
' endfor
' TextWindow.Write("LoadBG")
' TextWindow.Write(BGx1)
' TextWindow.Write(" ")
' TextWindow.Write(BGy1)
' TextWindow.Write(" ")
' TextWindow.Write(BGx2)
' TextWindow.Write(" ")
' TextWindow.Write(BGy2)
' TextWindow.WriteLine(" ")
endif
EndSub

SmallBasic Turtle Logo Source Code 2

The bit about Show/Hide Turtle was very time consuming. I do wish Small Basic has better Screen Buffer capabilities.



Turtle Logo in Small Basic
'by Harry Hardjono
'Turtle angle speed x1 y1 x0 y0
'Turtle move moveto penup pendown
'Turtle turn turnleft turnright
'Turtle show hide
'
' I did this in one afternoon. Could've been faster if I ignore Show/Hide Turtle

GraphicsWindow.Show()
GraphicsWindow.Clear()


beginloop:
GraphicsWindow.Clear()
cmd1="init"
Toitle()
Program.Delay(2000)
cmd1="hide"
Toitle()

For loop=1 to 50
cmd1="penup"
Toitle()
cmd1="moveto"
cmd2=Math.GetRandomNumber(sx)
cmd3=Math.GetRandomNumber(sy)
Toitle()
cmd1="pendown"
Toitle()
cmd1="color"
cmd2=GraphicsWindow.GetRandomColor()
Toitle()
cmd1="size"
cmd2=Math.GetRandomNumber(10)
Toitle()
' Show Turtle is very slow!
' If (loop=10) Then
' cmd1="show"
' Toitle()
' ElseIf (loop=30) then
' cmd1="hide"
' Toitle()
' EndIf
For loop2=1 to Math.GetRandomNumber(6)
cmd1="turn"
cmd2=Math.GetRandomNumber(360)
Toitle()
cmd1="move"
cmd2=Math.GetRandomNumber(1000)
Toitle()
endfor
endfor
Program.Delay(5000)
Goto beginloop



Sub Toitle
'cmd1=command (input)
'cmd2=param1 (input)
'cmd3=param2 (input)
If (cmd1="init") then
sy=GraphicsWindow.Height
sx=GraphicsWindow.Width
'Bug: GetPixel does not take Background color
GraphicsWindow.BrushColor="white"
GraphicsWindow.FillRectangle(0,0,sx,sy)
x1=sx/2
y1=sy/2
x0=x1
y0=y1
p=1
angle=180
col="blue"
GraphicsWindow.BrushColor=col
siz=1
ts=1
SaveBG()
elseif (cmd1="penup") then
p=0
elseif (cmd1="pendown") then
p=1
elseif (cmd1="move") then
'forward
LoadBG()
x0=x1
y0=y1
x1=x0+cmd2*Math.Sin(Math.GetRadians(angle))
y1=y0+cmd2*Math.Cos(Math.GetRadians(angle))
draw()
SaveBG()
elseif (cmd1="moveto") then
LoadBG()
x0=x1
y0=y1
x1=cmd2
y1=cmd3
draw()
SaveBG()
elseif (cmd1="turn") then
LoadBG()
angle=cmd2
SaveBG()
elseif (cmd1="turnleft") then
LoadBG()
angle=angle+cmd2
SaveBG()
elseif (cmd1="turnright") then
LoadBG()
angle=angle-cmd2
SaveBG()
elseif (cmd1="color") then
col=cmd2
elseif (cmd1="size") then
siz=math.Max(1,cmd2)
siz=math.Min(10,siz)
elseif (cmd1="show") then
if (ts<>1) then
ts=1
SaveBG()
endif
elseif (cmd1="hide") then
LoadBG()
ts=0
endif

'These really need to be Mod
'Seems buggy - doesn't work with negative number?
' RemBugFix2()
'x1=Math.Remainder(x1,sx)
'y1=Math.Remainder(y1,sy)
'angle=Math.Remainder(angle,360)

If (ts=1) then
DrawTurtle()
endif

endsub

Sub DrawTurtle
tx1=x1+10*Math.Sin(Math.GetRadians(angle))
ty1=y1+10*Math.Cos(Math.GetRadians(angle))
tx2=x1+10*Math.Sin(Math.GetRadians(angle+140))
ty2=y1+10*Math.Cos(Math.GetRadians(angle+140))
tx3=x1+10*Math.Sin(Math.GetRadians(angle+220))
ty3=y1+10*Math.Cos(Math.GetRadians(angle+220))
GraphicsWindow.FillTriangle(tx1,ty1,tx2,ty2,tx3,ty3)
endsub


Sub RemBugFix
While (px<0) px=px+sx EndWhile While (py<0) py=py+sy EndWhile endsub Sub RemBugFix2 While (x1<0) x1=x1+sx EndWhile While (y1<0) y1=y1+sy EndWhile While (angle<0) angle=angle+360 EndWhile endsub 'Draw Sub Draw If (p>0) then
If (x0<>x1 or y0<>y1) then
m=math.Max(math.Abs(x1-x0),math.Abs(y1-y0))
mx1=0
mx3=m
For i=0 To m
my1=x0
my3=x1
mx2=i
map()
px=my2
my1=y0
my3=y1
mx2=i
map()
py=my2
RemBugFix()
px=Math.Remainder(px,sx)
py=Math.Remainder(py,sy)
If (siz>1) then
GraphicsWindow.BrushColor=col
GraphicsWindow.FillEllipse(px,py,siz,siz)
else
GraphicsWindow.SetPixel(px,py,col)
endif
EndFor
endif
endif

'These really need to be Mod
'Seems buggy - doesn't work with negative number?
RemBugFix2()
x1=Math.Remainder(x1,sx)
y1=Math.Remainder(y1,sy)
angle=Math.Remainder(angle,360)

endsub

'map function
Sub map
'x1-x2-x3 y1-y2-y3
'(x2-x1)/(x3-x1)=(y2-y1)/(y3-y1)
'(y3-y1)*(x2-x1)/(x3-x1)=(y2-y1)
'y1+(y3-y1)*(x2-x1)/(x3-x1)=y2
my2=((my3-my1)*(mx2-mx1)/(mx3-mx1))+my1
EndSub


sub SaveBG
If (ts=1) then
BGc=0
BGx1=Math.Floor(Math.Max(0,x1-10))
BGx1=Math.Floor(Math.Min(sx,BGx1))
BGy1=Math.Floor(Math.Max(0,y1-10))
BGy1=Math.Floor(Math.Min(sy,BGy1))
BGx2=Math.Floor(Math.Max(0,x1+10))
BGx2=Math.Floor(Math.Min(sx,BGx2))
BGy2=Math.Floor(Math.Max(0,y1+10))
BGy2=Math.Floor(Math.Min(sy,BGy2))
For BGy=BGy1 To BGy2
For BGx=BGx1 To BGx2
BGc=BGc+1
BG_Array[BGc]=GraphicsWindow.GetPixel(BGx,BGy)
EndFor
endfor
' TextWindow.Write("SaveBG ")
' TextWindow.Write(BGx1)
' TextWindow.Write(" ")
' TextWindow.Write(BGy1)
' TextWindow.Write(" ")
' TextWindow.Write(BGx2)
' TextWindow.Write(" ")
' TextWindow.Write(BGy2)
' TextWindow.WriteLine(" ")
endif
endsub

Sub LoadBG
If (ts=1) then
BGc=0
For BGy=BGy1 To BGy2
For BGx=BGx1 To BGx2
BGc=BGc+1
GraphicsWindow.SetPixel(BGx,BGy,BG_Array[BGc])
EndFor
endfor
' TextWindow.Write("LoadBG")
' TextWindow.Write(BGx1)
' TextWindow.Write(" ")
' TextWindow.Write(BGy1)
' TextWindow.Write(" ")
' TextWindow.Write(BGx2)
' TextWindow.Write(" ")
' TextWindow.Write(BGy2)
' TextWindow.WriteLine(" ")
endif
EndSub

SmallBasic Turtle Logo Source Code

Just how hard is it to code a turtle? Not hard at all, if one hour is all it takes to code this. I'm still missing Show and Hide Turtle, but hey, it's only one hour!

'Turtle Logo in Small Basic

'by Harry Hardjono

'Turtle angle speed x1 y1 x0 y0

'Turtle move moveto penup pendown

'Turtle turn turnleft turnright

' Only took me 1 hour to do this. :)

'

GraphicsWindow.Show()

GraphicsWindow.Clear()

cmd1="init"

Toitle()

cmd1="move"

cmd2="50"

Toitle()

cmd1="turnright"

cmd2="90"

Toitle()

cmd1="move"

cmd2="50"

Toitle()

cmd1="turnright"

cmd2="90"

Toitle()

cmd1="move"

cmd2="50"

Toitle()

cmd1="turnright"

cmd2="90"

Toitle()

cmd1="move"

cmd2="150"

Toitle()

cmd1="turnleft"

cmd2="90"

Toitle()

cmd1="move"

cmd2="50"

Toitle()

cmd1="turnright"

cmd2="90"

Toitle()

cmd1="moveto"

cmd2="20"

cmd3="50"

Toitle()

cmd1="turn"

cmd2="20"

Toitle()

cmd1="move"

cmd2="1500"

Toitle()

cmd1="turnright"

cmd2="100"

Toitle()

cmd1="move"

cmd2="1500"

Toitle()

cmd1="turnright"

cmd2="100"

Toitle()

cmd1="move"

cmd2="1500"

Toitle()

cmd1="turnright"

cmd2="100"

Toitle()

cmd1="move"

cmd2="1500"

Toitle()

Sub Toitle

'cmd1=command (input)

'cmd2=param1 (input)

'cmd3=param2 (input)

If (cmd1="init") then

sy=GraphicsWindow.Height

sx=GraphicsWindow.Width

x1=sx/2

y1=sy/2

x0=x1

y0=y1

p=1

angle=90

elseif (cmd1="penup") then

p=0

elseif (cmd1="pendown") then

p=1

elseif (cmd1="move") then

'forward

x0=x1

y0=y1

x1=x0+cmd2*Math.Sin(Math.GetRadians(angle))

y1=y0+cmd2*Math.Cos(Math.GetRadians(angle))

draw()

elseif (cmd1="moveto") then

x0=x1

y0=y1

x1=cmd2

y1=cmd3

draw()

elseif (cmd1="turn") then

angle=cmd2

elseif (cmd1="turnleft") then

angle=angle+cmd2

elseif (cmd1="turnright") then

angle=angle-cmd2

endif

'These really need to be Mod

'Seems buggy - doesn't work with negative number?

RemBugFix2()

x1=Math.Remainder(x1,sx)

y1=Math.Remainder(y1,sy)

angle=Math.Remainder(angle,360)

endsub

Sub RemBugFix

While (px<0)

px=px+sx

EndWhile

While (py<0)

py=py+sy

EndWhile

endsub

Sub RemBugFix2

While (x1<0)

x1=x1+sx

EndWhile

While (y1<0)

y1=y1+sy

EndWhile

While (angle<0)

angle=angle+360

EndWhile

endsub

'Draw

Sub Draw

If (p>0) then

If (x0<>x1 or y0<>y1) then

m=math.Max(math.Abs(x1-x0),math.Abs(y1-y0))

mx1=0

mx3=m

For i=0 To m

my1=x0

my3=x1

mx2=i

map()

px=my2

my1=y0

my3=y1

mx2=i

map()

py=my2

RemBugFix()

px=Math.Remainder(px,sx)

py=Math.Remainder(py,sy)

GraphicsWindow.SetPixel(px,py,"blue")

EndFor

endif

endif

endsub

'map function

Sub map

'x1-x2-x3 y1-y2-y3

'(x2-x1)/(x3-x1)=(y2-y1)/(y3-y1)

'(y3-y1)*(x2-x1)/(x3-x1)=(y2-y1)

'y1+(y3-y1)*(x2-x1)/(x3-x1)=y2

my2=((my3-my1)*(mx2-mx1)/(mx3-mx1))+my1

EndSub